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is taken up by the veins, and a part thrown off by the skin, lungs, and various secretions, we shall see how gelatine may be formed out of albumen,

26. Osmazome is an element which exists in all the animal fluids, and in some of the solids, as the brain and muscular fibre. It is of a reddish brown colour, of an aromatic smell and agreeable taste) It is this which gives the strong flavour of roasted meat, and the peculiar taste of the various kinds of animal food. It is supposed to be tonic and stimu lating, but to possess no nutritive properties

27. Mucus is that bland fluid which moistens the surface of all the mucous membranes In some of the hard parts of the body, which are destitute of sensibility, it is found to exist in considerable quantities, as in the nails, hair, and cuticle of man, and in the scales, feathers, and wool of different animals. That part of the skin called rete mucoscum, is supposed to be compacted mucus. Mucus is transparent, has no colour or taste, and has a ropy and viscid consistence. When dry, it is insoluble in water. It contains much azote.

28. There are some other substances found in the human body, such as caseine, or that principle of the milk which forms the basis of cheese, curd, &c.; but they are not of sufficient importance to need a particular description.)

Questions. What is meant by the chemical composition of the body? What are some of the ultimate elements ? What are some of the proximate elements? How have the ultimate elements been divided? Is oxygen essential to all the proximate elements? What is said of hydrogen ?-Of carbon ?-Of Azote? How do oxygen, hydrogen, and azote get into the system? Is phosphorus found in animal bodies? What other elements are met with in animals? How are the organic elements of the body formed? How divided? What acids are found in animal bodies? What are the most important compounds in the body? What is said of albumen? In what is it found? What is fibrin the basis of? How may it be obtained from

blood? Of what is it composed? Where is gelatine found in the animal body? How known from the other animal principles? What does it form when dried? Of what is glue prepared? In what does gelatine exist? How may we account for the productions of gelatine? What is osmazome? What peculiar properties has it? What is mucus? Where found, what is its use? Are any other substances found in the human body?

CHAPTER VI.

THE HUMAN SKELETON.

1. Of all the wonderful works of the great Architect, none bears such convincing proofs of divine wisdom and goodness as the mechanism of the human body. Every part, down to the minutest fibre or blood-vessel, bears the impress of the Creator's hand, and the marks of design and contrivance are so obvious throughout, as to lead the mind irre. sistibly to an all-wise, Omnipotent designer!

The

2. The human skeleton consists of about 252 bones, including the sesamoid, the teeth, and the small bones of the ear; though they are generally reckoned at 211. They are divided into those of the head, trunk, and extremities, some of them being single, others in pairs. When the bones composing the skeleton are connected together by natural liga. ments, they form what is called a natural skeleton; when by wires, it is termed an artificial skeleton. The latter is the common and most useful mode of articulation to the anato. mist, as the joints can be easily moved and examined. skeleton has been called the bony frame work of the body, because by its form and solidity, it not only retains every part of the fabric in its proper shape, but also affords a hard surface for the attachment of muscles, and the protection of many important organs. If we suppose a plane to pass down from the top of the head through the middle of the skeleton, the latter will be divided into two equal portions, called the right and left side of the body, which are perfectly alike in shape and size. Those bones which are situated in the centre, such as the spine and breast bone, and are intersected by it, are said to be symmetrical, because they are divided equally; the others, such as the bones of the arm and leg, are in pairs.

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55

To these are sometimes added the proper bones of the ear, contained in the temporal bones.

2

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2

2

2

1

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32

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Total, 55

Mallei, (hammer)

Incudes, (anvil)

Stapedes, (stirrup).

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Orbicularia, (round bones) 2

4. The trunk contains 57 bones, viz:

Vertebræ, (a,)

Ribs, Costa, e, f, g,)`

Total, 8

21

24

2

2

1

Breast bone, (Sternum, c, d,)

Hip bones, (Ossa innominata, i,)
Rump bones, (Os sacrum, k,)
Coceygeal bones, (Ossa coceygis) 4

5. The upper extremities contain 68 bones, viz:
Collar bones, (Claviculæ, a,)
Shoulder blades, (Scapula, b,)
Arm bones, (Ossa humeri, c,)

Total, 57

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Fore arm bones, Radii et ulnæ, d, e,)

4

Wrist bones, (Ossa carpi, f,)

16

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